CN108708791B - Cam sliding type engine braking device - Google Patents
Cam sliding type engine braking device Download PDFInfo
- Publication number
- CN108708791B CN108708791B CN201810428991.1A CN201810428991A CN108708791B CN 108708791 B CN108708791 B CN 108708791B CN 201810428991 A CN201810428991 A CN 201810428991A CN 108708791 B CN108708791 B CN 108708791B
- Authority
- CN
- China
- Prior art keywords
- brake
- plunger
- cam
- braking
- exhaust
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
- F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
- F02D13/04—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation using engine as brake
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/02—Valve drive
- F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
- F01L1/047—Camshafts
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/34—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift
- F01L1/344—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear
- F01L1/34403—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear using helically teethed sleeve or gear moving axially between crankshaft and camshaft
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/46—Component parts, details, or accessories, not provided for in preceding subgroups
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
- F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
- F02D13/0242—Variable control of the exhaust valves only
- F02D13/0246—Variable control of the exhaust valves only changing valve lift or valve lift and timing
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Valve Device For Special Equipments (AREA)
Abstract
A cam sliding type engine braking device, a camshaft assembly (10) of an engine comprises a spline shaft (21) at least used for a cylinder and a braking and exhaust cam (22) which are connected by a spline, the braking and exhaust cam (22) is provided with an exhaust cam (31) and a braking cam (32) used for engine braking, the braking cam (32) is provided with two small peach-shaped points and a larger peach-shaped point, the braking and exhaust cam (22) is also provided with two spiral grooves (33, 34) and a positioning groove (35) with opposite rotation directions, a control mechanism (14) is arranged above the braking and exhaust cam (22) and is controlled by an electromagnetic valve (59), when the engine needs to be converted into an engine braking working state, the electromagnetic valve (59) is electrified and is driven by the electromagnetic valve or hydraulic power, the braking and exhaust cam (22) is moved by the action of the spiral groove, so that the roller of the exhaust rocker arm (11) is switched from being in contact with the exhaust cam (31) to being in contact with the braking cam (32), and the two-stroke engine braking is realized.
Description
Technical Field
The invention relates to a device for realizing engine braking by utilizing a cam sliding mode, belongs to the technical field of engines, and particularly relates to the technical field of engine braking.
Background
Engine braking technology has been available and used for a long time, particularly in heavy duty diesel engines. For heavy trucks, when long-term braking is required, such as when driving on a long downhill slope, a conventional service brake device (brake) is prone to failure due to overheating during long-term use, and thus greatly threatens the driving safety. When a vehicle equipped with the engine braking device runs, a driver starts the engine braking device according to needs, the engine cuts off fuel supply at the moment, the clutch keeps a state of being connected with the power output end of the engine, the vehicle drags the engine to rotate by the kinetic energy of the vehicle, and the engine braking device temporarily converts the engine into an air compressor consuming power by changing the timing and the lift of an air valve, particularly an exhaust valve, so as to realize a braking function. The engine braking device can greatly relieve the working load of the service braking device, greatly improves the running safety of the vehicle, and becomes a necessary configuration for heavy trucks at present.
The engine brake can be divided into compression release type brake and air release type brake, the compression release type brake is that in the compression stroke, when the piston is close to the compression top dead center, the exhaust valve is opened to release the compressed air entering the cylinder, and then the exhaust valve is closed when the piston enters the power stroke after passing through the top dead center. Bleeder brakes release compressed air by holding the exhaust valve slightly open during the non-exhaust stroke or only during the compression stroke of the engine, and generally have higher braking power and are applied more often than bleeder brakes.
At present, the engine braking device is mainly applied to a four-stroke heavy-duty diesel engine, and compression release type engine braking devices are more, in a working cycle (air inlet-compression-work-exhaust) of the four-stroke engine, the piston moves upwards once in each of the compression stroke and the exhaust stroke, theoretically, when the engine is converted into a braking state to work, the compression and exhaust strokes are both released to maximize the braking power, however, most of the compression-release engine brake devices that have been used so far cannot change the timing and lift of the exhaust valve for normal engine operation in the exhaust stroke, and therefore, the compression release of the air entering the cylinder during the compression stroke can only be achieved during one working cycle, resulting in a single braking, while a second braking is not possible during the exhaust stroke. In the technology disclosed at present, the brake is generated by performing compression release on compression and exhaust strokes, a plurality of rocker arms or a complex rocker arm or valve bridge structure is often needed, the structure is complex, the cost is high, and the working reliability is insufficient.
Disclosure of Invention
The invention provides an engine braking device which can realize that a piston is compressed and released to generate braking power in compression and exhaust strokes, namely, the piston moves upwards each time to generate a braking function, so that the effect of the engine braking function is exerted to the maximum, and the engine braking is also called as two-stroke braking.
The engine brake device of the invention consists of a camshaft assembly, an air inlet and exhaust rocker arm, a rocker arm shaft and a control mechanism. The camshaft assembly comprises a spline shaft, a braking and exhausting cam and an air inlet cam, wherein the spline shaft is processed into a spline on a shaft section between two supporting shaft necks, an inner hole of the braking and exhausting cam is a spline hole matched with the spline shaft, the minimum inner diameter of the spline hole is larger than the diameter of the supporting shaft neck on the spline shaft, the shaft neck can penetrate through the shaft neck to be sleeved on the spline shaft, and the shaft neck can freely slide on the spline shaft. The exhaust cam and the brake cam are processed on the brake and exhaust cam, the exhaust cam is provided with a peach point for exhausting when the engine works normally, the brake cam is provided with three peach points, wherein the smaller two peach points are symmetrically distributed and used for opening the exhaust valve to release compressed gas when the piston runs to the position near the top dead center every time in the braking state of the engine, and the other larger peach point is used for opening the exhaust valve in the power stroke of the engine to enable waste gas to enter the cylinder so as to realize the generation of braking by recompression and release during the exhaust stroke. And a braking spiral groove and a return spiral groove are also processed adjacent to the cam, the rotation directions of the two spiral grooves are opposite, and the spiral parts of the two spiral grooves are finally connected with the middle positioning groove. The inner hole of the air inlet cam is also a spline hole matched with the spline shaft, so that all cams of a plurality of cylinders can be assembled on the spline shaft, and meanwhile, the air inlet cam is provided with a positioning hole and is fixed on the spline shaft through a positioning pin, so that the axial movement of the air inlet cam is avoided.
The control mechanism consists of a controller body, a brake plunger, a return plunger, a plunger spring, a pressing plate bolt, a control rod, a pull rod spring, a clamp spring, a spring washer and an electromagnetic valve. The brake plunger and the return plunger are arranged in the controller body, each plunger is pressed upwards by a plunger spring, the plungers are pressed in the controller body by a pressing plate, the control rod is arranged on a shaft on the controller body, two cams of the control rod are respectively pressed on the brake plunger and the return plunger, a fork-shaped arm structure is arranged above the control rod and connected with a pull rod, a pull rod spring is arranged on the pull rod, clamp springs and gaskets are arranged at two ends of the spring, the clamp springs are clamped on the pull rod shaft and cannot axially move, the spring gaskets can axially move on the pull rod to compress the pull rod spring, and one end of the pull rod is connected with a driving shaft of the electromagnetic valve.
The working principle of the device is as follows: when the engine normally works, the lower end of the return plunger is inserted into a positioning groove in the middle of the two spiral grooves on the braking and exhaust cam to position the braking and exhaust cam at the axial position on the spline shaft, and at the moment, the roller on the exhaust rocker arm is in contact with the exhaust cam, so that the exhaust rocker arm opens and closes the exhaust valve according to the valve timing and the lift range of the engine in the normal working state. When the engine needs to be converted into an engine braking working state, the electromagnetic valve is electrified, the electromagnetic valve driving shaft pulls the pull rod, the pull rod applies acting force to the control rod through the pull rod spring, the control rod presses down the braking plunger at the moment, the return plunger bounces, the lower end of the braking plunger enters the spiral part of the braking spiral groove along with the rotation of the cam, the cam moves to one side under the action of the braking spiral groove, the lower end of the braking plunger finally enters the middle positioning groove to position the axial position of the braking and exhaust cam, and at the moment, the exhaust rocker roller is in contact with the braking cam, and the exhaust rocker opens and closes the exhaust valve according to the valve timing and lift in the engine braking. When the engine needs to quit the braking working state and returns to the normal working state, the electromagnetic valve is powered off, the electromagnetic valve driving shaft pushes the pull rod under the action of the electromagnetic valve spring, the braking plunger bounces under the action of the plunger spring and presses down the return plunger under the lever action of the cam on the control rod, at the moment, along with the rotation of the cam, the lower end of the return plunger enters the return spiral groove to enable the cam to move towards the other side, the exhaust rocker roller is in contact with the exhaust cam, and the engine returns to the normal working state.
Furthermore, the control mechanism is driven by hydraulic power, a brake plunger, a return plunger, a plunger spring, a one-way valve and the like are arranged in the controller body, lubricating oil with certain pressure of an engine is used as a driving source, the opening and closing of an oil inlet channel and an oil drain channel are controlled by an electromagnetic valve to control the extension and the bouncing of the brake plunger and the return plunger, and the brake and the exhaust cam move left and right to realize the brake state entering the engine and the brake state exiting the engine.
The device has the advantages that: 1. the device realizes that the piston is compressed and released to generate braking power in compression and exhaust strokes, namely the piston moves upwards each time to generate a braking action, so that the effect of the engine braking function is exerted to the maximum. 2. For a multi-valve engine with more than one exhaust valve, when the device is operated in a braking state, all the exhaust valves are driven simultaneously to carry out compression release to generate braking, and the braking power per unit displacement of the engine can be obviously improved. 3. The device has simple structure, low cost and easy application.
Drawings
FIG. 1 is an oblique sectional view and schematic illustration in normal operation of a first embodiment of the present invention;
FIG. 2 is an oblique cross-sectional view of the camshaft assembly of the present invention;
FIG. 3 is a schematic view of the brake and exhaust cam structure of the present invention and a cross-sectional view of the detent;
FIG. 4 is a cam lift curve for the brake cam and exhaust cam of the present invention;
FIG. 5 is a schematic view of a control mechanism according to a first embodiment of the present invention;
FIG. 6 is a schematic illustration of the first embodiment of the present invention in an engine braking mode of operation;
FIG. 7 is a schematic view of a control mechanism according to a second embodiment of the present invention and is shown in a normal operating condition;
fig. 8 is a schematic structural diagram of a controller body according to a second embodiment of the present invention;
FIG. 9 is a schematic illustration of the second embodiment of the present invention in an engine braking mode of operation;
detailed description of the preferred embodiments
Fig. 1 to 6 illustrate a first embodiment of the present invention, in which the brake device includes a camshaft assembly 10, exhaust rocker arms 11, a rocker shaft 13, and a control mechanism 14, as shown in fig. 1. The camshaft assembly 10 is installed on an engine cylinder cover, the control mechanism 14 is installed above or on the side of the camshaft assembly 10, the exhaust rocker arm 11 and the intake rocker arm 12 are installed on a rocker shaft 13, and the exhaust rocker arm 11 and the intake rocker arm 12 are both roller type rocker arms. Fig. 2 illustrates the structure of the camshaft assembly 10 of the present embodiment, in which the camshaft assembly 10 includes a spline shaft 21 for at least one cylinder and a brake and exhaust cam 22, and the spline shaft 21 is formed as a spline on the shaft section between two support journals. Fig. 3 illustrates the structure of the brake and exhaust cam 22, the inner hole of the brake and exhaust cam 22 is a spline hole matched with the spline shaft 21, and the minimum inner diameter of the spline hole is larger than the diameter of the support shaft neck on the spline shaft, so that the brake and exhaust cam 22 can penetrate through the support shaft neck to be sleeved on the spline shaft and can freely slide on the spline shaft. The exhaust cam 31 and the brake cam 32 are processed on the brake and exhaust cam 22, the exhaust cam 31 and the brake cam 32 are provided with base circles with the same diameter, one peach-shaped tip is arranged on the exhaust cam 31 and used for exhausting when the engine works normally, three peach-shaped tips are arranged on the brake cam 32, two smaller peach-shaped tips are symmetrically distributed and used for opening the exhaust valve to release compressed gas when the piston runs to the position near the top dead center each time in the engine braking state, and the other larger peach-shaped tip is used for opening the exhaust valve when the engine works to enable exhaust gas to enter the cylinder, so that the exhaust gas is compressed again to release to generate braking when the exhaust stroke is performed. Fig. 4 shows a schematic diagram of the exhaust cam 31 lift and the small lobe lift and the large lobe lift of the brake cam 32 in relation to the cam angle during one cam rotation period. With the top dead center of the compression stroke of the engine as 0 degree cam angle, the two small peak lifts of the brake cam 32 are respectively positioned near the cam angles of 0 degree and 180 degrees, the larger peak lift of the brake cam 32 is positioned in the range of 0 degree to about 90 degrees cam angle (power stroke), the exhaust cam 31 and the brake cam 32 have a common base circle part B (as shown in figure 3), and the exhaust cam and the brake cam have no lift (as shown in figure 4) in the range of B and are also the base circle part. And a braking spiral groove 33 and a return spiral groove 34 are processed adjacent to the cam, the rotating directions of the two spiral grooves are opposite, a guide section of a straight line section is arranged before the two spiral grooves enter the spiral section, and the spiral parts of the two spiral grooves are finally connected with a middle positioning groove 35. When the plunger with a fixed position is inserted into the braking or returning spiral groove, the braking and exhausting cam 22 moves to the left or right side under the action of the spiral groove along with the rotation of the cam shaft, and finally the plunger enters the positioning groove 35 in the middle.
In particular, the relative positions in the circumferential direction of the spiral portions of the braking spiral groove 33 and the return spiral groove 34 of the braking and exhaust cam 22 and the common base circle portion (B segment) of the exhaust cam 31 and the braking cam 32 are characterized as follows: when the camshaft assembly rotates, the roller of the exhaust rocker arm 11 is always in contact with the common base circle portion (section B) of the exhaust cam 31 or the brake cam 32 in the process of moving the brake and exhaust cam 22 left and right by inserting the plunger into the brake or return spiral groove.
The inner hole of the air inlet cam 23 is also a spline hole matched with the spline shaft 21, so that all cams of a plurality of cylinders can be conveniently assembled on the spline shaft, and meanwhile, the air inlet cam is provided with a positioning hole and is fixed on the spline shaft through a positioning pin 24, so that the axial movement of the air inlet cam is avoided.
Fig. 5 depicts the control mechanism structure of the engine brake device, and the control mechanism is composed of a controller body 50, a brake plunger 51a, a return plunger 51b, a brake plunger spring 52a, a return plunger spring 52b, a pressure plate 53, a control rod 54, a pull rod 55, a pull rod spring 56, a snap spring 57a, a snap spring 57b, a spring washer 58 and an electromagnetic valve 59. The braking plunger 51a and the return plunger 51b are installed in the controller body 50, a braking plunger spring 52a and a return plunger spring 52b are respectively installed below the braking plunger 51a and the return plunger 51b, the two plungers are respectively subjected to upward pre-tightening force of the braking plunger spring 52a and the return plunger spring 52b, the pre-tightening force of the braking plunger spring 52a is obviously greater than that of the return plunger spring 52b, and the two plungers are pressed in the controller body by a pressing plate 53. The control rod 54 is mounted on a shaft on the controller body 50 and can swing around the shaft, the control rod 54 is provided with a fork-shaped arm at the upper end, two cams are arranged below the fork-shaped arm and press on the brake plunger 51a and the return plunger 51b respectively, the pull rod 55 penetrates through the fork-shaped arm at the upper end of the control rod 54, the pull rod 55 is provided with a pull rod spring 56, the spring is provided with a snap spring 57a, a snap spring 57b and a spring washer 58 at two ends, the snap spring 57a and the snap spring 57b are clamped on the pull rod shaft and cannot move along the axial direction, the width and the height of the snap spring 57b are smaller than the width and the height of the middle of the fork-shaped arm at the upper end of the control rod 54, the drive shaft of the electromagnetic valve 59 can penetrate through the fork-shaped arm at the upper end of the control rod 54, the diameter of the spring washer 58 is larger than the width of the middle of, the compression pull rod spring 56 can be moved axially on the pull rod 55, and the resulting moment of action of the preload of the pull rod spring 56 on the control rod 54 is greater than the resulting moment of action of the brake plunger spring 52a on the control rod 54, which ensures that when the pull rod spring 56 is compressed, the preload of the pull rod spring 56, via the spring washer 58, on the control rod 54 is sufficient to depress the brake plunger 51 a. One end of the pull rod 55 is connected to a drive shaft of the solenoid valve 59.
In the first embodiment of the present invention, when the engine normally operates, as shown in fig. 1, the electromagnetic valve 59 is not energized, there is no force between the fork arm at the upper end of the control rod 54 and the pull rod spring 56, because the pre-tightening force of the brake plunger spring 52a is significantly greater than the pre-tightening force of the return plunger spring 52b, the brake plunger 51a springs upward under the action of the brake plunger spring 52a, the fork arm at the upper end of the control rod 54 swings to the side of the return plunger 51b, the return plunger 51b is pressed down, the lower end of the return plunger 51b is inserted into the positioning slot 35 between the two spiral grooves on the brake and exhaust cam 22, and the brake and exhaust cam 22 is axially positioned on the spline shaft 21, at this time, the roller on the exhaust rocker arm 11 contacts with the exhaust cam 31, so that the exhaust rocker arm opens and closes the exhaust valve according to. When the engine needs to be switched to the engine braking operation state, as shown in fig. 6, the electromagnetic valve 59 is energized, the electromagnetic valve driving shaft pulls the pull rod 55, the pull rod 55 and the snap springs 57a and 57b on the shaft thereof move to one side of the electromagnetic valve along with the pull rod, the pull rod spring 56 is compressed and applies acting force to the control rod 54 through the spring washer 58, the acting moment generated on the control rod 54 by the pre-tightening force of the pull rod spring 56 is larger than the acting moment generated on the control rod 54 by the braking plunger spring 52a, at this time, the control rod 54 presses the braking plunger 51a, the return plunger 51b is bounced under the force of the return plunger spring 52b, at this time, the lower end of the braking plunger 51a enters the guide part of the braking spiral groove 33, along with the rotation of the cam, the lower end of the braking plunger 51a enters the spiral part of the braking spiral groove 33, the braking and, and finally enters the middle positioning groove 35 to position the axial position of the braking and exhaust cam 22, at the moment, the roller of the exhaust rocker arm 11 is contacted with the braking cam 32, and the exhaust rocker arm 11 opens and closes the exhaust valve according to the cam lift curve of the engine braking state. In the engine braking state, the return plunger 51b is sprung up with its lower end aligned with the guide portion of the return spiral groove 34. When the engine needs to exit from the braking operation state and return to the normal operation state, the electromagnetic valve 59 is powered off, the electromagnetic valve driving shaft moves the pull rod 55 and the snap springs 57a and 57b on the shaft thereof to one side far away from the electromagnetic valve along with the pull rod under the action of the spring in the electromagnetic valve and the pull rod spring 56, at this time, the spring washer is contacted with the snap spring 57b, the fork arm at the upper end of the control rod 54 is not pressed by the pull rod spring 56 any more, because the pretightening force of the braking plunger spring 52a is obviously greater than the pretightening force of the return plunger spring 52b, the braking plunger 51a bounces upwards under the action of the braking plunger spring 52a, the cam on the control rod 54 is pushed to make the control rod 54 swing to one side of the return plunger 51b, the return plunger 51b is pressed down by overcoming the pretightening force of the return plunger spring 52, the braking and exhaust cam 22 is axially positioned on the spline shaft 21, the roller on the exhaust rocker arm 11 is contacted with the exhaust cam 31 at the moment, and the engine returns to the normal working state.
In the first embodiment of the present invention, the control rod 54 of at least one cylinder is controlled by the pull rod 55, the control rod 54 of all cylinders can be controlled by a plurality of cylinders by the pull rod 55, when the control rod of a plurality of cylinders is controlled, the electromagnetic valve 59 is electrified, all the control rods are simultaneously acted by the pull rod spring 56, and the brake plunger of each cylinder can make each cylinder enter an engine brake state one by one according to the phase sequence of the cam of each cylinder.
In the first embodiment of the present invention, as described above, since the roller of the exhaust rocker arm 11 is always in contact with the base circle portion (B segment) common to the exhaust cam 31 or the brake cam 32 during the leftward or rightward movement of the brake and exhaust cam 22 by the plunger, there is no force between the exhaust rocker arm roller and the cam, ensuring that the exhaust and brake cam 22 can slide freely during sliding and does not interfere with the adjacent cam. In addition, when the control rod 54 controls the brake plunger 51a and the return plunger 51b to press down and bounce in a side-to-side manner, one side always bounces and the other side is pressed down due to the lever action, so that one plunger can be ensured to be withdrawn from the positioning groove 35 before entering the brake spiral groove 33 or the return spiral groove 34, the interference is avoided, and the working reliability of the device is ensured.
Fig. 7 to 9 illustrate a second embodiment of the invention, in which the only difference from the first embodiment is the control mechanism. Unlike the first embodiment in which the control mechanism 14 is purely mechanically driven, the second embodiment employs a hydraulic drive using engine oil as a power source. As shown in fig. 7, the control mechanism is composed of a controller body 71, a brake plunger 72, a brake plunger spring 73, a return plunger 74, a return plunger spring 75, a check valve 76, a plug 77a, a plug 77b, and a solenoid valve 78. As shown in fig. 8, a brake plunger hole 81 and a return plunger hole 82, an oil inlet passage 83, an oil drain passage 84 and a check valve oil passage 85 are formed in the controller body 71, and the brake plunger 72 and the return plunger 74 are respectively installed in the brake plunger hole 81 and the return plunger hole 82 in the controller body 71. A brake plunger spring 73 is arranged below the brake plunger 72 and used for jacking the brake plunger, and a step is arranged on the shaft section below the brake plunger 72 and used for limiting the downward moving position of the plunger. A return plunger spring 75 is mounted above the return plunger 74, a step is provided below the return plunger hole 82, the step is located above the oil inlet passage 83, and the return plunger 74 is pressed against the step by the return plunger spring 75. It is noted in particular that the pre-tensioning force of the brake plunger spring 73 is significantly greater than the pre-tensioning force of the return plunger spring 75, but at the same time it is ensured that the lubricating oil under pressure acts on the volume above the brake plunger 72 when the engine is running, pressing it down. A plug 77a and a plug 77b are mounted above the brake plunger 72 and the return plunger 74, respectively, for sealing the plunger bore and defining the position of the plunger for upward movement. A check valve oil passage 85 in the controller body 71 communicates the volume between the brake plunger 72 and the plug 77b and the oil inlet passage 83, and a check valve 76 is installed in the check valve oil passage 85 so that the lubricating oil can enter the volume above the brake plunger 72 through the oil inlet passage 83 and cannot flow in the reverse direction. The controller body 71 is provided with a solenoid valve 78, a driving shaft of the solenoid valve controls opening and closing of an oil inlet passage 83 and an oil drain passage 84, the oil inlet passage 83 is communicated with a lubricating oil passage of an engine with certain pressure, when the solenoid valve 78 is not electrified, a driving shaft of the solenoid valve bounces upwards to close the oil inlet passage 83 and open the oil drain passage 84, and when the solenoid valve 78 is electrified, the driving shaft of the solenoid valve extends downwards to open the oil inlet passage 83 and close the oil drain passage 84.
In the second embodiment of the present invention, during normal operation of the engine, as shown in fig. 7, the electromagnetic valve 78 is not energized, the oil inlet 83 is closed, the oil drain 84 is opened, the brake plunger 72 and the return plunger 74 are in upward springing and downward extending states respectively under the action of the brake plunger spring 73 and the return plunger spring 75, the lower shaft of the return plunger is inserted into the positioning groove 35 between the two spiral grooves of the brake and exhaust cam 22, and the upper roller of the exhaust rocker arm 11 is in contact with the exhaust cam 31, so that the exhaust rocker arm opens and closes the exhaust valve according to the exhaust cam lift curve in the normal operation state of the engine. When the engine needs to be switched to the engine braking operation state, as shown in fig. 9, the electromagnetic valve 78 is energized to open the oil inlet passage 83, the oil drain passage 84 is closed, the engine lubricating oil with a certain pressure enters the volume below the return plunger 74 through the oil inlet passage 83 and enters the volume above the brake plunger 72 through the check valve, since the pre-load of the brake plunger spring 73 is significantly greater than the pre-load of the return plunger spring 75, upon receiving the lubricating oil pressure, the return plunger 74 is first raised and then the brake plunger 72 is depressed, as described above in the first embodiment, under the action of the spiral groove on the braking and exhaust cam 22, the braking and exhaust cam 22 will move to one side, making the roller of the exhaust rocker arm 11 contact with the braking cam 32, and causes the exhaust rocker arm 11 to open and close the exhaust valve in accordance with the cam lift curve of the engine braking state. When the engine needs to exit from the braking operation state and return to the normal operation state, the electromagnetic valve 78 is powered off, the oil inlet channel 83 is closed, the oil drain channel 84 is opened, at this time, the lubricating oil in the two plunger holes leaks through the oil drain channel 84 under the action of the two plunger springs, and because the pretightening force of the braking plunger spring 73 is obviously greater than the pretightening force of the return plunger spring 75, the lubricating oil above the braking plunger 72 is firstly drained and bounced by the braking plunger spring 73, then the lubricating oil below the return plunger 74 is drained and pressed down by the return plunger spring, the braking and exhaust cam 22 is moved to the other side in the same manner as the first embodiment, so that the roller on the exhaust rocker arm 11 is in contact with the exhaust cam 31, and the engine returns to the normal operation.
In the second embodiment of the present invention, the solenoid valve 78 controls the opening and closing of the oil inlet passage 83 and the oil drain passage 84 on the controller body 71 of at least one cylinder, and for a multi-cylinder engine, the solenoid valve 78 can control the opening and closing of the oil inlet passage 83 and the oil drain passage 84 on the controller body 71 of a plurality of cylinders up to all cylinders, so as to achieve the lowest cost. In the embodiment, the pretightening force of the brake plunger spring 73 is set to be obviously greater than the pretightening force of the return plunger spring 75, so that the brake plunger 72 and the return plunger 74 can be pressed down and bounced in sequence when the engine enters the braking state and exits the braking state of the engine, the two plungers cannot be pressed down or bounced simultaneously, the interference is avoided, and the working reliability of the device is ensured.
Claims (3)
1. A cam-slide type engine brake device comprising: exhaust rocking arm (11), rocking arm axle (13), camshaft assembly (10) and control mechanism (14), its characterized in that: camshaft assembly (10) of engine has included spline shaft (21), braking and exhaust cam (22) that are used for an at least cylinder, braking and exhaust cam (22) are installed on spline shaft (21), processing has exhaust cam (31) and brake cam (32) on braking and exhaust cam (22), there is a peach point on exhaust cam (31), there are three peach points on brake cam (32), wherein less two peach points are the symmetric distribution, and its angular position who installs on spline shaft (21) sets up to: the engine opens the exhaust valve when the piston runs to the position near the top dead center each time, and the angle position of the other larger peach point arranged on the spline shaft is set as follows: the exhaust valve is opened when the engine does work, an exhaust cam (31) and a brake cam (32) on the brake and exhaust cam (22) are provided with base circles with the same diameter and a common base circle part (B section) in the circumferential direction, a brake spiral groove (33) and a return spiral groove (34) are further processed on the brake and exhaust cam (22), the two spiral grooves are opposite in rotation direction, and the angle positions of the two spiral grooves distributed in the circumferential direction relative to the angle positions of the common base circle part (B section) are set as follows: when the camshaft assembly (10) rotates, in the process of enabling the brake and the exhaust cam (22) to move left and right by inserting the brake or the return spiral groove into the plunger, the roller of the exhaust rocker arm (11) is always in contact with the common base circle part (B section), a positioning groove (35) is further processed between the brake spiral groove (33) and the return spiral groove (34), the positioning groove (35) is an annular groove distributed on the whole circumference, the two spiral grooves are finally connected with the positioning groove (35) in the middle, the control mechanism (14) is installed above or on the side of the brake and exhaust cam (22), the brake plunger and the return plunger, the brake plunger spring and the return plunger spring are installed in the control mechanism (14), the pretightening force of the brake plunger spring is obviously greater than that of the return plunger spring, and the control mechanism (14) is provided with an electromagnetic valve, the extension and retraction of the brake plunger and the return plunger are controlled by a solenoid valve.
2. A cam-slide type engine brake apparatus according to claim 1, wherein: the control mechanism (14) is provided with a controller body (50), a control rod (54) and a pull rod (55), the control rod (54) is arranged on a shaft on the controller body, the upper end of the control rod (54) is provided with a fork-shaped arm, two cams are arranged below the control rod (54) and respectively pressed on a brake plunger (51a) and a return plunger (51b), a pull rod spring (56) is arranged on the pull rod (55), snap springs (57a), snap springs (57b) and a spring washer (58) are arranged at two ends of the spring, the snap springs (57a) and the snap springs (57b) are clamped on the pull rod shaft and cannot move along the axial direction, the width and the height of the snap springs (57b) are smaller than the width and the height of the middle of the fork-shaped arm at the upper end of the control rod (54), the diameter of the spring washer (58) is larger than the width of the middle of the fork-shaped arm at the upper end of the, acting force is generated on a fork arm at the upper end of the control rod (54) through a spring washer (58), acting moment generated on the control rod (54) by the pre-tightening force of a pull rod spring (56) is larger than acting moment generated on the control rod (54) by a brake plunger spring (52a), the control rod (54) of at least one air cylinder is controlled by the pull rod (55), and one end of the pull rod (55) is connected with a driving shaft of a solenoid valve (59).
3. A cam-slide type engine brake apparatus according to claim 1, wherein: the control mechanism (14) is provided with a controller body (71) and a one-way valve (76), the controller body (71) is processed with a brake plunger hole (81), a return plunger hole (82), an oil inlet channel (83), an oil drain channel (84) and a one-way valve oil channel (85), the brake plunger (72) and the return plunger (74) are respectively installed in the brake plunger hole (81) and the return plunger hole (82) in the controller body (71), a brake plunger spring (73) is installed below the brake plunger (72), a step is arranged on a shaft section below the brake plunger (72), a return plunger spring (75) is installed above the return plunger (74), a step is arranged below the return plunger hole (82) and located above the oil inlet channel (83), the oil inlet channel (83) is communicated with a lubricating oil channel with certain pressure of an engine, the volume below the return plunger (74) and the volume above the brake plunger (72) are communicated by the one-way valve oil channel (85) in the controller body (71) The oil inlet channel (83) is opened and the oil drain channel (84) is closed when the electromagnetic valve (78) is powered on, and the oil inlet channel (83) is closed and the oil drain channel (84) is opened when the electromagnetic valve (78) is powered off.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810428991.1A CN108708791B (en) | 2018-04-27 | 2018-04-27 | Cam sliding type engine braking device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810428991.1A CN108708791B (en) | 2018-04-27 | 2018-04-27 | Cam sliding type engine braking device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108708791A CN108708791A (en) | 2018-10-26 |
| CN108708791B true CN108708791B (en) | 2020-05-05 |
Family
ID=63867709
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810428991.1A Active CN108708791B (en) | 2018-04-27 | 2018-04-27 | Cam sliding type engine braking device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108708791B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102019203233A1 (en) * | 2019-03-11 | 2020-09-17 | Mahle International Gmbh | Valve control |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102011076726A1 (en) * | 2011-05-30 | 2012-12-06 | Schaeffler Technologies AG & Co. KG | Valve train for combustion piston engine, has actuating device with rocker arm, which is arranged adjacent to control body in radial manner with axial alignment, where rocker arm is pivoted around tangential axis |
| CN104564201A (en) * | 2013-10-21 | 2015-04-29 | 大众汽车有限公司 | Device for adjusting camshaft of internal combustion engine |
| DE102013223299A1 (en) * | 2013-11-15 | 2015-05-21 | Schaeffler Technologies AG & Co. KG | Sliding cam system with extended single track area |
| DE102013113349A1 (en) * | 2013-12-03 | 2015-06-03 | Dr. Ing. H.C. F. Porsche Aktiengesellschaft | Sliding cam system with a lock |
| CN105863765A (en) * | 2016-05-18 | 2016-08-17 | 宁波圣龙汽车动力***股份有限公司 | Sliding type cam shaft with variable valve lift |
| CN106703924A (en) * | 2016-12-13 | 2017-05-24 | 大连理工大学 | Intensive hydraulic axial-movement type three-stage variable valve driving system and control method thereof |
-
2018
- 2018-04-27 CN CN201810428991.1A patent/CN108708791B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102011076726A1 (en) * | 2011-05-30 | 2012-12-06 | Schaeffler Technologies AG & Co. KG | Valve train for combustion piston engine, has actuating device with rocker arm, which is arranged adjacent to control body in radial manner with axial alignment, where rocker arm is pivoted around tangential axis |
| CN104564201A (en) * | 2013-10-21 | 2015-04-29 | 大众汽车有限公司 | Device for adjusting camshaft of internal combustion engine |
| DE102013223299A1 (en) * | 2013-11-15 | 2015-05-21 | Schaeffler Technologies AG & Co. KG | Sliding cam system with extended single track area |
| DE102013113349A1 (en) * | 2013-12-03 | 2015-06-03 | Dr. Ing. H.C. F. Porsche Aktiengesellschaft | Sliding cam system with a lock |
| CN105863765A (en) * | 2016-05-18 | 2016-08-17 | 宁波圣龙汽车动力***股份有限公司 | Sliding type cam shaft with variable valve lift |
| CN106703924A (en) * | 2016-12-13 | 2017-05-24 | 大连理工大学 | Intensive hydraulic axial-movement type three-stage variable valve driving system and control method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108708791A (en) | 2018-10-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101501039B1 (en) | Dedicated rocker arm engine brake | |
| US8813719B2 (en) | Internal combustion piston engine with a compression relief engine brake | |
| JP5344821B2 (en) | System and method for variable valve actuation in an internal combustion engine | |
| US20110220052A1 (en) | Internal combustion piston engine with an adjustable inflating element | |
| EP2318669B1 (en) | Bias system for dedicated engine braking rocker arm in a lost motion system | |
| US20170241305A1 (en) | Engine Braking Method and System | |
| CN102159800B (en) | Engine braking device for an internal combustion engine | |
| CN1038497A (en) | Rocker arm decoupler for two-cycle engine retarder | |
| EP3105427A1 (en) | Rocker arm assembly for engine braking | |
| WO2012048300A4 (en) | Positive control (desmodromic) valve systems for internal combustion engines | |
| CN108708791B (en) | Cam sliding type engine braking device | |
| EP2513436B1 (en) | Veb excenter reset | |
| CN109113829B (en) | Engine braking device | |
| CN201666172U (en) | System for actuating engine valve | |
| WO1994028290A1 (en) | Valve control apparatus and method | |
| CN213684263U (en) | Novel compression release type engine in-cylinder brake device | |
| CN110566315A (en) | Compression release type in-cylinder brake device for engine | |
| CN110700917A (en) | Compression release type in-cylinder brake device for engine | |
| CN109356730B (en) | Switchable push rod type engine braking device | |
| US20110036315A1 (en) | Valve lift control apparatus | |
| CN210919173U (en) | Compression release type in-cylinder brake device for engine | |
| CN211116163U (en) | Engine valve bridge device integrating braking function | |
| CN213838700U (en) | Compression release type in-cylinder brake device for engine | |
| CN113530633B (en) | Internal combustion engine cylinder braking device with three rocker arm structure | |
| RU2186994C2 (en) | Retarder for internal combustion engine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |